In the related art, sound production components using piezoelectric elements have been proposed, for example, in Patent Literature 1 and 2 described below. FIG. 14 is a schematic cross-sectional view of a portion of a piezoelectric sound production component described in Patent Literature 1. As shown in FIG. 14, the piezoelectric sound production component 100 includes a piezoelectric vibrator 101. The piezoelectric vibrator 101 includes a disk-shaped vibration plate 101a and a piezoelectric element 101b attached to the vibration plate 101a. The vibration plate 101a is attached at the entire circumference thereof to a case 103 through a support member 102.
In the piezoelectric sound production component 100, the support member 102 is formed in a curved shape. Thus, in the piezoelectric sound production component 100, the piezoelectric vibrator 101 can be greatly displaced. Therefore, in the piezoelectric sound production component 100, high output can be obtained.
Meanwhile, Patent Literature 2 states that a vibration plate is formed into a rectangular shape. When the vibration plate has a rectangular shape, the vibration amplitude of the vibration plate is determined by the length of the diagonal line. Thus, when the rectangular vibration plate is used, the equal vibration amplitude can be obtained with a vibration plate smaller than that when a circular vibration plate is used. Therefore, a piezoelectric sound production component can be reduced in size. In other words, when the vibration plate is formed into a rectangular shape, a piezoelectric sound production component having a small size but high output can be realized.    PTL 1: Japanese Unexamined Patent Application Publication No. 2001-339791    PTL 2: International Publication No. 2007/097077A1